“Siteel”, denominated by the author in 1959, is defined as follows: Siteel is a high strength Fe-Sialloy containing less than 0·025% C, more than 2·3% Si, some amount of Mn, Ni, Cr, Mo, etc., andthe balance essentially Fe, in which the total amount of the Ni and Mn is varied so as to approach twotimes of the Si content to lower the Ac3 transformation point below 750°(1400°F), thereby preventingthe alloy from grain-growth which usually lowers the toughness.
This new alloy can be easily cast, rolled and cold-drawn and has many valuable characteristics whichare superior to those of alloy steels such as NiCrMo structural steel SNCM 1 (AISI 4337) and 18-8stainless steel SUS 32, (AISI 316). Consequently siteel can be beneficially used for various applicationsrequiring high strength and toughness, and at the same time excellent corrosion and erosion resistances.
Siteel was produced on trial in some steel making plants, Kubota Iron Works and Japan Steel Works, with remarkable success.
In this paper, the general characteristics and some typical applications of four kinds of siteel aredescribed, and new standards of 18-8 stainless steels containing 3-4% Si are proposed for realization of the industrial production of these high silicon alloys.